Machine for grinding wooden clubs



1965 c. MEINECKE ETAL 3,215,355

MACHINE FOR GRINDING WOODEN CLUBS Filed Aug. 20, 1965 2 Sheets-Sheet 1 Nov. 2, 1965 c. MEINECKE ETAL 3,215,356

MACHINE FDR GRINDING WOODEN CLUBS 2 Sheets-Sheet 2 Filed Aug. 20, 1963 United States Patent 3,215,356 MACHINE FUR GRINDDJG WOUDEN CLUBS Curt Meinecite, Braunschweig, and Gerhard Hermann,

Gross-Denlrte, Germany, assignors to Miag Muhlenbau untl Industrie G.m.b.H., Braunschweig, Germany, a German company Filed Aug. 20, 1963, Ser. No. 303,445

Claims priority, application Germany, Aug. 22, 1962, M 53,977; Nov. 21, 1962, M 54,890 Claims. (Cl. 241-281) The invention disclosed herein is concerned with a machine for grinding wooden clubs, comprising chains forming a shaft through which club blanks are moved downwardly and pressed against a grinding wheel.

The drawbacks of machines of the above indicated kind, which have been known for a long time, resides in that complicated and costly gears are required for driving the chains so as to make it possible, on the one hand, to lower the chain mountings so as to compensate for the wear of the grinding wheel and on the other hand, to effect upward displacement thereof so as to permit exchange of the grinding wheel. Further disadvantages result in this connection from the requirement that the chain mountings must be firm with respect to each other, so as to avoid any alteration of the width of the shaft and to also avoid any unsymmetrical load on the grinding wheel, the latter feature being particularly desirable so as to maintain between the wall of the shaft and the grinding wheel tangent, at the point of which the grinding starts, an angle which departs as little as possible from 90.

The grinder according to the invention overcomes the above mentioned drawbacks and effects considerable reduction in costs, by the provision of two frames disposed upon the base which encloses the grinding wheel, said frames being laterally adjustable and having means for vertically adjustably supporting the mountings which are mutually separably connected and which carry the chains and individual drives therefor.

The operation is effected with the aid of hydraulic devices, hereinafter referred to as hydraulic presses or, briefly, as presses, which are adapted to provide for a very quick and well adjustable vertical motion of the chain mountings. Spindles are additionally provided for setting or fixing the adjustment effected by the hydraulic presses. Upon connecting the two presses to only one pressure system, there will be automatically assured a completely uniform operation of the two pressure systems, since the mountings are guided in the laterally adjustable frames provided therefor. Of the two guide points of a chain frame, one will always lie at the bottom of the frame while the other is to be arranged thereabove. This may be effected by a superstructure on the frame or by the raising press or by a guide in the form of angular profiles disposed at the top of the chain mounting, which may be arranged, for example, in the break-through of the ceiling of a floor. There must be considered in this connection the lateral adjustability which depends upon the guide frames of the chain mountings.

Details of the invention will now be explained in the description which is rendered below with reference to the accompanying drawings showing an embodiment thereof.

FIG. 1 shows a grinder, representing the chain mountings only partially, the left half of the figure showing a vertical section as seen along line II of FIG. 3, and the right half showing an elevational side view as seen when looking in the direction of the arrow Z in FIG. 3;

FIG. 2 represents an elevational view as seen when looking in the direction Y of FIG. 1;

3,215,355 Patented Nov. 2, 1965 FIG. 3 illustrates a transverse section as seen along line IIIIII in FIG. 1;

FIG. 4 indicates part of the chain mounting;

FIG. 5 shows in schematic manner and partially in sectional view a device for driving the chains; and

FIG. 6 is a graph showing the function scheme for the device according to FIG. 5.

The grinder comprises the following principal parts: Base 1 with the grinding wheel 2; frames 3 with two hydraulic presses 4, and two similar mountings 5 each with two chains 6 and associated drive means. The machine stands upon a suitable foundation.

The base 1 is formed by a box-like structure provided with ribs and top and bottom flanges. The grinding wheel is in known manner fastened on a shaft 21 which is journalled for rotation in bearings 22 disposed on separate mountings adjacent to the base 1.

Upon the base 1, along the sides of the grinding wheel 2, are disposed the U-shaped frames 3, by means of screws 31, so that their spacing from the vertical plane 8 which bisects the axis 21, can be adjusted. Since the two frames 3 are independently adjustable, the spacing of the right hand frame 3 from the median plane 8 may be greater, at given shaft width, than the spacing of the left hand frame 3 from such median plane 8, with the consequence that the angle 9 between the horizontal and the tangent at the grinding wheel 2 is at the running-in place made as small as possible, which is desirable for technological reasons.

Each frame 3 carries a hydraulic press 4 which is disposed upon the transverse beam of the respective U- shaped frame 3, a positioning spindle 32 being fastened to each of the two end beams.

The chain mounting 5 (see also FIG. 4) comprises substantially the U-shaped base member 51 from the legs 51 of which extend the upwardly directed parts 52. At the top of the transverse member of the base part 51 is provided the part 53. The U-shaped base part 51 is terminated at the bottom by a trough-like part 51". The two uprights 52 of a mounting are provided with bores 52 (FIG. 4), through which are extended rods 54 which are disposed parallel to the shaft 21 of the grinding wheel. Profiled bars 54' are fastened to the rods 54 between the uprights 52 and parallel thereto. The rollers 6' of the chains 6 engage the flanges of the profiled bars 54. Members 54" are provided for slightly tensioning the chain mountings 5 with respect to one another, such members 54" being readily adjustably disposed at the end of the members 54, as is apparent from the figure. Near the bottom of the legs 51 of the base member 51 are provided the bearings 55' for the bottom shafts 67 of the respective chains, chain wheels 68 being fastened to such shafts. At the ends of the shafts 67 which face the bearings 55' are disposed the flanges 66 forming ratchcts for the chain pawl drive which is actuated by the hydraulic presses 7, 7'. The latter will be presently described more in detail.

The two portions of the chains which are disposed in opposition to one another form a shaft extending up to the upper chain wheels, not shown, with the opposed portions of such chains moving downwardly. The shaft so formed is filled with wooden clubs 10 which are supplied thereto more or less continuously in small quantities. The clubs are gripped by the chain links 6, fed downwardly thereby and pressed against the rotating grinding stone 2 which, with the aid of water, defibrates the clubs in known manner.

Plates or sheets 57 are provided for covering the shaft on the sides thereof, such plates being tensioned with respect to one another, thereby reinforcing the structure. The action of the diagonal tensioning is already obtained by engagement of the edges of the plate 57 with the tubular member 54 which project from the uprights 52, as is indicated in FIG. 1.

A spray nozzle 58 is arranged in the space between the bottom chain part and the lower chain wheel 68 for spraying the running rollers 6' of the chain 6 and also the gaps between the teeth of the chain wheels so as to remove moist grinding material adhering thereto. The function of the nozzle is important for the proper operation of the machine.

The upper guiding of the chain mounting 5 with respect to the frames 3 is in the illustrated embodiment effected by guide collars 53 disposed below the boxes 53 of the base 51, the pistons of the hydraulic presses 4 projecting into the respective collars.

Both hydraulic presses are advantageously connected to the same hydraulic system so as to obtain identical force-and load conditions. The mountings are moreover Supported by spindles 32 of the frames 3, by means of flanges 59 which are welded to the leg portions 51' of the base 51, such flanges 59 being clamped between nuts disposed upon the respective spindle. These additional supporting means are as such known; they serve to fix the height adjusted by the hydraulic presses 4, thus relieving the presses of a continuous load.

The drive shafts 67 of the chains 6 must be driven with practically constant and relatively very low speed of revolution while exerting a constant relatively great torque. Suitable for this purpose are at least two pawlratchet drives which are alternately actuated by hydraulic presses.

The control must be such, especially for the start of the operation, that the uniform functioning of the controlled interplay is reliably obtained at any position of the two hydraulic presses.

In order to satisfactorily solve the problem involved, the invention proposes a drive which comprises a changeover control and a switch, both forming part of the respective hydraulic presses, such change-over control actu ating shortly before the conclusion of the power stroke of the piston, the change-over control of the other bydraulic press in such a manner that the piston of the other hydraulic press is caused to execute the power stroke, the teeth of the pawl-ratchet wheels being angularly displaced with respect to one another. The first mentioned hydraulic press is the master press and the other is the follower press. The hydraulic master press is shown at the top of FIG. 5.

Each driven chain shaft 67 is provided with two ratchet wheels 66, 66', each with eight teeth, resulting in an angle of division w:45. Upon the shaft 67 are also provided the pawl carriers 13, 13', to which are linked the spring biased pawls 14, 14'. The drive of the pawls is effected by means of the hydraulic presses 7, 7' the piston rods 60, 60 of which cooperate in known manner with parts 15 of the pawl carriers. Each hydraulic press 7, 7 is provided with a changeover press 80, 80', which is in the case of the master press 7 connected with electrical switches 81, 82 and in the case of the follower press 7' with the electromagnet 84. The piston rod 60 carries a control rod 61 which is by means of two link members 62 connected with the shift rod 83 of the change-over device 80. The control rod 61 of the hydraulic master press 7 carries an extension 60" which engages the left end of the shift rod 83 when the piston rod 60 is near its right end position, thereby taking the shift rod 83 along and effecting in known manner the switching-over of the hydraulic master press 7.

Each change-over device 80, 80 is made in the form of a known hydraulic shift switch with a pressure line 91, two distributor lines 93, 94 and two return lines 92. Each hydraulic press 7, 7 is provided with an annular cover 71 through which extends the respective piston rod 60, 60', and cover 72 at the other end which contains the pressure controlled check valve 73. The cover 72 is also provided with a fixed auxiliary piston 74 which projects into a bore 63 formed in the respective piston rod 60, 60', and contains an oil feed line 75 which is by way of the bore 76 connected with the distributor line 94 and otherwise closed by the pressure controlled check valve 73. The latter is controlled by means of the small spring biased piston 77 and is by way of line 78 connected with the larger side of the piston 69 from which extends the piston rod 60. The smaller piston 77 is effected by pressure via the line 95 which is branched off from the distributor line 94. The shift rod 83 of the change-over or switch-over device 80 is by means of a flexible member 96' connected with the positive terminal of the line 96 and can conduct the current in its right end position, by way of contact 88 to the counter 89 which is by way of line 90 connected to the negative terminal. Near the other end of the switch-over device 80 of the hydraulic master press 7 is provided the electrical switch 81 having a contact 85 disposed upon the shift rod 83, which contact is electrically connected with the housing contact 86 responsive to pulling out of the shift rod 83. This is the case when the piston rod 60 with its control rod 61 stretches the link members 62. Closure of the switch 85, 86 connects over the line 97 current to the electromagnet 84 which causes positioning of the switch-over device 80', cooperatively associated with the piston rod 60 of the hydraulic follower press 7, into power stroke position, shortly before the master piston 69 has concluded its power stroke.

The hydraulic system comprises the pumps 11 for the hydraulic master press and the pump 12 for the hydraulic follower press. Both pumps are disposed in the reservoir 16 and are driven by the motor 17 with the aid of a gear 17 operating with continuously adjustable gear ratio.

In the illustrated position, the oil flows from the pump 11 by way of the line 91 to the change-over device 89 and thence by way of the lines 94, 76, 75 into the cylinder 63 of the piston rod 60. Since the amount of oil supplied is constant, the piston 69 will be rapidly driven forwardly until the pawl 14 is in engagement with the tooth of the ratchet wheel 66 which is nearest to it. It may be mentioned at this place that the illustrated position of the hydraulic master press 7 does not practically occur, since the shaft 67 rotates continuously and since the piston, upon reaching its initial position, reaches in rapid advance the next tooth of the ratchet which moves ahead thereof. However, the position shown in FIG. 5 is assumed to constitute the initial position which may be adjusted. The rapid advance which is otherwise always present, therefore is here equal to zero, since the pawl 14 engages the associated tooth and gives off work to the shaft 67. Accordingly, the pressure increases, causing opening of the valve 73 thus permitting oil to reach through the bore 78 the end of the piston 69. The speed of such piston therefore drops suddenly at such instant and the working stroke commences. The links 62 are stretched responsive to the motion of the piston 60 to the right, taking along the shift rod 83, whereby the switch 85, 86 is closed and the switch-over device 80' 0f the follower is actuated by the electromagnet 84; consequently, as described before, the piston rod 60' of the hydraulic follower is set in motion and the master piston 60, 69 is switched over and returns, since the oil from the line 91 now flows by way of the line 93 and the bore 79 in the annular cover 71, to the smaller side of the piston 69. Since the left end of the piston is smaller than the right end, while the amount of oil delivered in a time unit is constant, the piston will move faster in the return stroke than in the power stroke. Shortly before reaching the initial position, the extension 60" on the control rod 61 will move the shift rod 83 back and will effect the switching over of the hydraulic master press. The counter 89 is coincidently actuated responsive to connection of the shift rod 83. with contact 88.

The operation is similar in the case of the hydraulic follower press, except that the control rod 61 remains in the position indicated by dot-dash lines, so that the shift rod 83' is not affected by the action of the piston rod 60. The switch-over device 80' is controlled by the electromagnet 84 in the manner already described. This results in a control of the hydraulic follower press 7 which depends upon the motion of the master piston 69, whereby the drive from any position of the two hydraulic presses falls into the proper working play at the latest after one working beat of the hydraulic master press 7.

This will be explained with reference to the function scheme shown in FIG. 6.

Upon the ordinate is plotted the division angle w of the ratchet wheels 66, 66' and on the abscissa is plotted the time in units 2. The points of this diagram are hereinafter given in terms of socalled angle-times, noting first the time value 2 and after a traction stroke following such time value, the respective angle in fractional decimal values of 1. The position of the hydraulic master press 7, shown in FIG. 5, is marked by the point 0.5/ 0 lying on the abscissa of the diagram. The line a extending from this point signifies the angular path of the ratchet tooth driven by the master press 7 over the entire division angle range w. The partial line b coinciding with the line a, does not practically occur, as previously noted, passing at the point 1.05/ 0.25 over into the line b, at which point the pawl 14 normally catches up with the respective tooth, which is the case at the juncture of the line 0 with the line a. This will be presently explained again. From this point of (105/025), the pawl on the tooth will jointly move, the shaft 67 will be driven, which is the case up to the point 2.5/1. Ahead of this, the contact 85, 86 of the switch-over device 80 of the hydraulic master press 7 is closed at the point 2.2/0.85, and the hydraulic follower 7 is responsive to actuation of its switchover device 80' affected by the electromagnet 84 to execute the power stroke. This is effected according to line d of the diagram with a rapid motion until the pawl has at the point 2.3/0.4 caught up with the respective pawl, following the line e. When the piston rod 60 of the hydraulic master press reaches along the line a the point 2.5/ 1, there is effected the switching-over, in the manner described, and the piston rod 60 moves back, in accordance with the line 1, to the point 3.0 which corresponds to the point 1/0. After this instant is to be considered the next following tooth, requiring going back to point 1/0, left in the diagram. As will be seen, upon reaching the points 3/0 or 1/0, respectively, the rapid operation of the master piston is set in motion according to line 0, until the transmission of force between the pawl 14 and the following tooth is restored again at the point 1.05/025. The play of the hydraulic master press along the lines g, h, a, i, k(:g) etc., of the ratchet teeth (the lines 11 and i represent the jumping from a ratchet tooth under consideration, to the next successive tooth in the line zero) as well as along the line course I, m, c, b, of the impact area of the pawl 14, is continuously operative and dependent only upon the adjusted amount of oil which the master press is supplied.

As described above, the piston rod 60' of the follower press 7', after executing its rapid motion d, has caused its pawl 14 to engage at the diagram point 2.3/0.4 the tooth lying next ahead thereof and has from thereon operated in driving sense. (The diagram point 25/05 for the tooth is identical with the diagram point 0.5/ 0.5 for the succeeding tooth.) The lines n for the ratchet tooth and p for the pawl rise at the last noted point jointly in power transmitting sense, up to the point 1.5/ 1, the pawl returning at such point with accelerated motion according to line q to the diagram point 2.0. Ahead of this phase, namely, at the diagram point 1.9/0.2, in which the motion line q of the pawl crosses with the motion line e of the next following tooth, the pawl falls upon the back of the following tooth. After the pawl has dropped and the piston rod 60 has come to rest, it will remain Without angular motion, according to line r, up to the instant 2.2 (see the arrow at the angular value 0.58 of the line a) when the reconnection of the piston of the follower press is effected in the described manner, by the action of the piston of the master press.

This control secures reliable operation, likewise, starting from any position of the two presses, and absorption of discrepancies of return motion due to fabrication inaccuracies. The line q for the return of the pawl 14' of the piston 60' can extend from the point 1.5/1 more or less inclined, without detrimentally affecting the function; a stronger inclined curve, that is, a quicker return motion of the follower piston, practically does not occur, since the speed is with properly tightly seated piston, given by the amount of oil supplied; however, a slower return may be caused by lacking tightness and in such case, the line q will be flatter. In the event that the follower piston returns so slowly that it does stop in its end position, which may be readily observed at the machine, such condition will indicate an obvious fault and the machine should be checked, although the function of the interplay as such is not yet doubtful. This is only the case when a master piston reverses its motion prior to the dropping of the pawl, which means, however, that the intersection point of the lines q and e lies in the diagram at the right of the time mark 2.5. However, the master piston can according to the lines In and 1 return much slower without affecting the function. This only happens when the line c intersects the lines b at the right of the time mark 1.5, which can occur only in the presence of serious faults in the machine which can be detected by many known means before causing trouble.

The illustrated mechanical arrangement can be modified. It is, for example, possible to fixedly link the piston rods to the pawl holders 13, 13' while pivotally suspending the presses 7, 7'. Uniform construction of both presses and the pawl-ratchet mechanism is advantageous for reasons of simplicity and far-reaching coordination of the working strokes, as may be seen from the diagram, for example, line b between the points /025 and 15/05. It is also readily possible to provide an arrangement with dissimilar presses and pawl-ratchet mechanisms, wherein one group needs to effect only a bridging stroke with smaller angular extent, so as to control the drive of the shaft during the return motion of the master piston.

The control may be effected with various modifications, for example, fully hydraulic or fully electric. The switchover device may be utilized to operate as a relay for the control of a switch-over piston, as may be indicated in an installation of relatively great size.

The particular advantages of the use of the drive according to the invention reside in that the drive may always be uniformly constructed irrespective of the spacing of the conveyor chains, further, that the chains can be individually operated so as to avoid vacant spaces at the feed-in of the wooden clubs, and that the operating speed of revolution can be very finely adjusted, by the use of hydraulic adjustment pumps, or, as illustrated, by gears which are continuously adjustable, that is, adjustable without stages. Adjustment pumps may be relatively very small as compared with a mechanical finely continuously regulatable drive.

The motion acceleration provides the advantage of quickly utilizing the full pressing force of the chains.

The fact that great forces can be readily produced by the use of hydraulic means, further, that the pawl carrier may be constructed as a long lever, makes it possible to construct the drive according to the invention aside from its use in connection with the particular grinder, so as to reliably control great forces with lowest speed of revolution.

Changes may be made within the scope and spirit of the appended claims in which is defined what is believed new and desired to have protected by Letters Patent.

We claim:

1. A machine for grinding wooden clubs, comprising a base containing a grinding wheel rotatably disposed therein, conveyor chains, forming partial walls delimiting a shaft extending vertically upwardly from said base, for downwardly transporting clubs to press such clubs against said grinding wheel, a pair of frames disposed upon said base and being laterally adjustable with respect thereto, an upright mounting extending from such frame, each mounting carrying a chain and drive means therefor, means for separably connecting said mountings, and means for vertically adjustably disposing said mountings to adjust the spacing of said chains with respect to said grinding wheel.

2. A machine according to claim 1, comprising means for guiding said mountings at points above the respective frames.

3. A machine according to claim 1, comprising hydraulic means for guiding said mountings at points above the respective frames.

4. A machine according to claim 1, comprising threaded spindles and hydraulic devices fastened on the respective frames, for guiding said mountings at points above such frames.

5. A machine according to claim 1, comprising threaded spindles and hydraulic devices fastened on the respective frames, for guiding said mountings at points above such frames, and means for connecting said hydraulic devices to the same hydraulic system.

6. A machine according to claim 1, comprising a spray device disposed in the space above the bottom drives for said chains.

7. A chain drive device comprising a plurality of chains, a shaft carrying toothed ratchets for respectively driving said chains, a pawl for each ratchet, a hydraulic press for operatively actuating each pawl, one of said presses constituting a master press and the other constituting a follower press, and means for controlling the actuation of said follower press depending upon the piston motion of the master press.

8. A chain drive device according to claim 7, wherein the tooth divisions of said ratchets are mutually displaced, a switch-over device for said master press and for said follower press, respectively, a switch operable by the switch-over device of said master press for causing the switch-over device of said follower press to operate shortly before conclusion of .the power stroke of the piston of the master press, whereby the piston of said follower press is actuated to execute a power stroke.

9. A chain drive device according to claim 8, comprising a fixed piston extending into a bore formed in the piston of the respective presses, a channel formed in the respective fixed piston, and means for connecting said channel with a pressure line and by way of a check valve with another line terminating ahead of the end of the piston of said master press.

10. A machine for grinding wooden clubs, comprising a base containing a grinding wheel rotatably disposed therein, conveyor chains, forming partial walls delimiting a shaft extending vertically upwardly from said base, for downwardly transporting clubs to press such clubs against said grinding wheel, a pair of frames disposed upon said base and being laterally adjustable with respect thereto, an upright mounting extending from such frame, each mounting carrying a chain and drive means therefor, each of said driving means comprising a shaft carrying toothed ratchets for driving the respective chains, a pawl for each ratchet, a hydraulic press for operatively actuating each pawl, one of said presses constituting a master press, and the other a follower press, and means for controlling the actuation of said follower press depending upon the piston motion of the master press, means for separably connecting said mountings, and means for vertically adjustably disposing said mountings to adjust the spacing of said chains with respect to said grinding wheel.

References Cited by the Examiner UNITED STATES PATENTS 1,465,069 8/23 Warren 241281 1,948,189 2/34 Russel et al 241281 2,445,081 7/48 Pouille 91-189 2,626,487 1/53 Janusauskas 5l-'76 2,965,077 12/60 Van Den Bussche 91-189 3,024,576 3/62 Barron et al. 51-76 LESTER M. SWINGLE, Primary Examiner. 

1. A MACHINE FOR GRINDING WOODEN CLUBS, COMPRISING A BASE CONTAINING A GRINDING WHEEL ROTATABLY DISPOSED THEREIN, CONVEYOR CHAINS, FORMING PARTIAL WALLS DELIMITING A SHAFT EXTENDING VERTICALLY UPWARDLY FROPM SAID BASE, FOR DOWNWARDLY TRANSPORTING CLUBS TO PRESS SUCH CLUBS AGAINST SAID GRINDING WHEEL, A PAIR OF FRAMES DISPOSED UPON SAID BASE AND BEING LATERALLY ADJUSTABLE WITH RESPECT THERETO, AN UPRIGHT MOUNTING EXTENDING FROM SUCH FRAME, EACH MOUNTING CARRYING A CHAIN AND DRIVE MEANS THEREFOR, MEANS FOR SEPARABLY CONNECTING SAID MOUNTINGS, AND MEANS FOR VERTICALLY ADJUSTABLY DISPOSING SAID MOUNTINGS TO ADJUST THE SPACING OF SAID CHAINS WITH RESPECT TO SAID GRINGIND WHEEL. 